Insert Disc 2. At the main menu, select the "Publicity" option. Highlight the "Publicity And Merchandising" and press Down three times to highlight a hidden "DVD Credits" option on the left side of the screen. Press Enter to view the disc's production credits.

Hidden web site reference (20th Anniversary Collector's Edition)

Allow the main menu animations to cycle. "www.tronkillerapp.com" will eventually appear on the screen. Go to that URL and click on the option that states you have level 6 clearance to view a full screen Macromedia Flash animation that suggests a sequel to the movie.